set of rationals not multiple of an $n$-th power of a prime
Source: JBMO 2008 Shortlist N2
October 14, 2017
JBMOnumber theory
Problem Statement
Let be a fixed positive integer. An integer will be called "-free" if it is not a multiple of an -th power of a prime. Let be an infinite set of rational numbers, such that the product of every elements of is an -free integer. Prove that contains only integers.